Unicode Explained

Type Invocation Meaning

int compareTo(Character) Comparison using code numbers

int digit(char,int) Numeric value of the character, using the radix specified by the second argu-

ment

boolean equals(Object) Tests for equality by char value

boolean isDefined(char) Tests whether the code point is assigned

boolean isDigit(char) Tests for being a decimal digit—i.e., gc = Nd

boolean isHighSurrogate(char) Tests for being a high surrogate code unit

boolean isISOControl(char) Tests for being a C0 or C1 Control character

boolean isLetter(char) Tests whether gc is Lu, Ll, Lt, Lm, or Lo

boolean isLetterOrDigit(char) Either isLetter or isDigit returns true

boolean isLowSurrogate(char) Tests for being a high surrogate code unit

boolean isSpace(char) Tests for space character: gc is Zs, Zl, or Zp

boolean isTitleCase(char) Tests whether gc = Lt

The Preparedness Principle

Well-written program code is prepared for handling any input data, even data that

should not occur. Handling may of course consist of simply detecting an error and, for

example, skipping erroneous data silently, skipping it with a warning message, or re-

porting an error and terminating. In writing a subroutine that will not be called from

outside our program, we might consider relying on the caller to pass correct data only,

to save both programming and execution time. When writing library routines, espe-

cially if they perform complex tasks, the ...